7/17/2012 5:41 AM
Researchers at Rice University in Houston have made a breakthrough in the production of batteries, creating a new power source that can be sprayed on surfaces like paint. Although still in prototype form, the technology could hold promise for a number of professional production devices, making them smaller, lighter and even offering a power source in remote areas where none currently exists.
The researchers have created five sprayable paints that form a lithium-ion battery when layered together, allowing users to store energy on walls, tiles or even on personal items like coffee mugs.
Conventional batteries contain a positive and negative electrode, both paired with a metal current collector, and a polymer separator sandwiched in the middle, according to the website New Scientist (http://newscientist.com/).” These five layers are usually manufactured in sheets and rolled up into a cylinder to form the battery. This process makes it hard to create extremely thin batteries.
Neelam Singh and his colleagues at Rice used a combination of existing metallic paints and custom materials to make sprayable versions of each layer. This allowed the creation of batteries just a fraction of a millimeter thick by airbrushing the layers onto a surface, one at a time.
The Rice team applied their batteries to a variety of ordinary building materials and even a ceramic coffee mug to test their potential. Nine bathroom tile batteries charged by a solar cell were able to power 40 LEDs arranged to spell out “RICE” for six hours.
The new battery technology doesn’t yet match conventional technology. A paintable battery, the researchers said, would currently have to be about 1.5 square feet to match a standard mobile phone battery. That, however, can improve quickly and is expected to with time.
“Their capacity, efficiency and performance could be vastly improved if made on an industrial scale,” Singh told New Scientist.
Also, the paints must currently be applied in a moisture and oxygen-free environment onto surfaces heated to 120 degrees C, hardly a simple process for users in the field.
“The focus of our ongoing research is to develop new battery materials which would not be degraded by air or moisture, non-toxic and safe to handle and use at home by non-experts, and environmentally friendly during use and disposal,” Singh told New Scientist.